Effects seem to always be global

[Portamento]

I've only had Affinity Designer for a few days. In the past, I've used Photoshop, although I'm not an expert. My favorite Adobe program was Fireworks, which has been discontinued.

I'm trying to do a very basic thing — set part of a photo to a heavy blur, but whatever I do, the Gaussian Blur seems to always affect the entire photo. (Yes, I could select part of my photo and add it to another Layer but, in the other programs I've used, there was always a quick way to only affect the part of the image which was Selected.)

In testing this, with a simple document, these are my Steps:

1. create new document
2. switch to Pixel Persona
3. select the Paint Brush Tool
4. set Width to 110px
5. set Flow to 100%
6. set Hardness to 100% (Steps 4, 5 and 6 are only to create a sharp image, so I can more easily see the results of the blurring effect.)
7. select a blue color
8. draw 5, horizontal strokes, each separated from the others
9. select the Rectangular Marquee
10. draw a selection down through all the strokes but leave parts of them unselected
11. select Effects from the right-side panel
12. put a Checkmark in Gaussian Blur
13. drag the Radius past 15px and "everything" is blurred. Why? Why isn't the blur only applied to the parts of the image "within" the Selection?

I see the same results if I use the Selection Brush Tool (or Rectangular Marquee).

If I select the Paint Brush Tool and draw across this page, it only paints within the Selection, which is what it's supposed to do. Why is Gaussian Blur ignoring the selected area?

Yes, I've tried using the Blur Brush Tool but, no matter how I adjust those Settings, it's effect is extremely weak.

I have watched a few Affinity Designer videos and searched this Forum but could not find an answer to this. I'm sure it's something very simple that I'm "doing" or "not doing".

[GarryP]

Welcome to the forums @Portamento

An Effect will always be applied to the whole of the layer (and the child layers of that layer, if there are any) which it is applied to – you can think of Effects as Layer Effects – and pixel selections do not affect this.
If you want to blur things individually like this, in Designer, then you will need to draw things individually, or isolate them, and then add a blur to each that needs a blur.

However, if you were using Photo then you would have much more control over what you can do, for example by using a Gaussian Blur Live Filter which has its own Mask.

The Pixel Persona of Designer is very nice but it - by design - has its limits when it comes to pixel-based manipulations, and that’s what Photo is for.

[Pšenda]

2 hours ago, GarryP said:

that’s what Photo is for

Personally, I was surprised to use ADesigner in the context of Photoshop.

14 hours ago, Portamento said:

In the past, I've used Photoshop,

 

[Old Bruce]

After step 10 do a Copy and Paste. This will make a copy of the Pixel Layer Selection and that layer can have the fx applied to it.

But honestly, for this sort of work Photo is a better choice. Pixel work and fx layers are limited, Life Filter layers in Photo are much more robust.

[carl123]

This video shows how to separate the layer effects from a layer onto their own layer

You can then add a mask (using a selection or otherwise) to only show part of the layer effect

Seems to work on all layer effects other than (you guessed it) Gaussian Blur

But this may be useful to someone in the future, currently browsing this forum.

And if you are currently browsing this forum from the future, please let us know, "do we eventually cure Covid or is it still around?"

Thanks